Install Python Packages Using pip

PyPi Statistics¶

You can check download statistics of Python Packages on PYPI at https://pypistats.org/. This is especially helpful if you want to choose from multiple packages.

Prefer Virtual Environment + pip¶

Virtual environment + pip is the preferred way to install Python packages.

Install pip¶

pip should be already available when you create a Python virtual environment.

Bootstrapping the pip Installer¶

The package ensurepip provides support for bootstrapping the pip installer into an existing Python installation or virtual environment.

sudo python3 -m ensurepip

Install a Specific Version of a Python Package¶

List all available versions of a Python package.
```
 :::bash
 pip3 install pylibmc==
```
Install a specific version of a Python package.
```
 :::bash
 pip3 install MySQL_python==1.2.2
```
Install pyarrow with a verison of at least 0.14.0. Notice that you must quote pyarrow>=0.14.0 using single/double quotes.
```
 :::bash
 pip3 install 'pyarrow>=0.14.0'
```
Install a Python package with a version in a range.
```
 :::bash
 pip3 install "jupyterlab>=1.2.7,<2.0.0"
```
You can install the pre-release version of a package using the --pre option. For example, the current version of pybuilder (0.11.7) is not compatible with Python 3.7. If you are using Python 3.7 and still want to use the pybuilder package, you can install the pre-release version (0.12) which is compatible with Python 3.7.
```
 :::bash
 pip3 install --pre pybuilder
```

Install Python Packages from Source¶

Install Python package from a tar.gz file which contains the source code.
```
 :::bash
 pip3 install xinstall-0.23.0.tar.gz
```
Install from the current directory
```
 :::bash
 pip3 install .
```
pip 20.0+ supports instaling a peotry managed Python project from GitHub directly. For example, the comamnd below installs the Python package dsutil from the GitHub repository dclong/dsutil directly.
```
 :::bash
 pip3 install git+ssh://git@github.com/dclong/dsutil 
 # or
 pip3 install git+https://github.com/dclong/xinstall
 # or install with optional components
 pip3 install --user -U "dsutil[all] @ git+https://github.com/dclong/dsutil@main"
 pip3 install "dsutil[cv] @ file:///home/dclong/dsutil-0.54.1-py3-none-any.whl"
 pip3 install "dsutil[cv] @ https://github.com/dclong/dsutil/releases/download/v0.54.1/dsutil-0.54.1-py3-none-any.whl"
```
If you are behind a corporate proxy, you might need 2FA to visit the enterprise GitHub of your company. However, 2FA is usually not required for Git comamnd line (since it would too much hassle). The above way to install Python packages from GitHub repositories directly can be a good way to avoid 2FA authentication if you are behind a corporate proxy.

Install Python Packages from Requirements.txt¶

You can install Python packages from a requirements.txt file.

:::bash
pip3 install -r requirements.txt

Notice that all formats accepted by pip3 install is valid in requirements.txt. For example, git+https://github.com/dclong/dsutil@master is valid to use in requirements.txt.

Difference between --ignore-installed and --force-reinstall¶

Sometimes a package is installed by distutils which cannot be reinstalled using pip, not even with the --force-reinstall option. In that case, you have to use the --ignore-installed option. For more discussions, please refer to Difference Between Pip Install Options Ignore Installed and Force Reinstall and blockstack-core::Issues 504 .

Install Python Packages Without Installing Dependencies¶

You can install a Python package without installing its dependencies using the command below.

:::bash
pip3 install --no-deps some_package

Upgrade Python Packages¶

You can upgrade an already installed Python package to the latest version using the command below.

:::bash
pip3 install --upgrade wheel

List All Installed Python Packages¶

List all installed modules.
```
 :::bash
 pip3 list
```
List outdated modules only.
```
 :::bash
 pip3 list --outdated
```
You can also use help('modules') to show all installed modules in Python.

Use pip with Proxy¶

You can export environment variables http_proxy and https_proxy or you can use pip with the --proxy option directly.

pip3 --proxy http://proxy__server_ip:port install some_pkg

When using the --proxy with pip/pip3, you can omit http:// and the port if the port is 80.

pip3 --proxy 10.135.227.47 search notifiers

Notice that sometimes pip does not respect the environment variables. In that case, you have to use the option --proxy to pass proxy to pip. And even with the option --proxy, pip might not work well if you install from a version control system. Just be ware of that. ProxyChains is likely a solution when that issue happens.

Misc¶

pip supports downloading Python packages without installing them. At the same time, you can disable pip caching using the option --no-cache-dir. For more discussions, please refer to Caching .
export LC_ALL=C resolves an issues (cannot remember which issue exactly) of pip3.

Installation Location¶

Please refer to The Installation Location of Python Packages Using Pip for more discussions.

Check for Existence of a Python Package¶

https://stackoverflow.com/questions/14050281/how-to-check-if-a-python-module-exists-without-importing-it

The most robust way turns out to be pip3 list, because some packages are namespace sub packagess which are not exposed (visible to importlib) by default. However, all installed packages (via pip) are visible to pip.

:::bash
pip3 list | grep -i pelican-render-math

References¶

https://stackoverflow.com/questions/38613316/how-to-upgrade-pip3

https://adamj.eu/tech/2019/03/11/pip-install-from-a-git-repository/

http://stackoverflow.com/questions/36394101/pip-install-locale-error-unsupported-locale-setting

http://unix.stackexchange.com/questions/87745/what-does-lc-all-c-do

https://stackoverflow.com/questions/4888027/python-and-pip-list-all-versions-of-a-package-thats-available

https://stackoverflow.com/questions/5226311/installing-specific-package-versions-with-pip

https://stackoverflow.com/questions/14149422/using-pip-behind-a-proxy

https://stackoverflow.com/questions/9510474/removing-pips-cache

https://stackoverflow.com/questions/36898474/how-to-install-a-module-for-all-users-with-pip-on-linux

How to pip install a package with min and max version range?

How to state in requirements.txt a direct github source

‘pip install’ From a Git Repository

🟣 Add a command for managing pip's cache

pypa/pip#6391